We report the synthesis and structural characterization of moderately air stable metal rich metallaboranes of iridium. Treatment of [Cp*IrCl2]2with BH3·thf at high temperature led to the isolation of a trimetallic [nido-5-(Cp*Ir)3B7H11], 1. Compound 1 is isoelectronic and isostructural with decaborane-14 where three BH units in [B10H14] have been replaced by Cp*Ir fragments. As far as we are aware, 1 is the first example of a iridadecaborane having three metals. In addition to the formation of 1, a change in the reaction conditions enabled us to isolate a 7 sep [(Cp*Ir)3B4H4], 2. The geometry of 2 can be viewed as a condensed polyhedron composed of Ir3B3octahedron capped by a BH unit. All the compounds have been characterized by IR and1H,11B, and13C NMR spectroscopy in solution, and the solid-state structures were established by X-ray crystallographic analysis. Quantum-chemical calculations by DFT methods for compounds 1 and 2 showed reasonable agreement with the experimentally observed structural parameters. The large HOMO–LUMO gaps are consistent with the high stabilities of the iridium clusters compared to their known Rh and Co analogues. © 2016 Elsevier B.V.

Sundargopal Ghosh

Department Of Chemistry

Rosmita Borthakur

Rini Prakash

Purbasha Nandi

boron

Boron Compounds

Iridium

Nuclear magnetic resonance spectroscopy

Quantum chemistry

Transition metals

X ray crystallography

13C NMR SPECTROSCOPY

DECABORANES

IRIDABORANE

Quantum chemical calculations

Solid-state structures

Structural characterization

Structural parameter

X-ray crystallographic analysis

Iridium compounds

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Organometallic Chemistry

Thermolysis of diphenyl dichalcogenides, Ph2E2 (E = S, Se and Te) with an insitu generated intermediate, obtained from the reaction of [Cp*WCl4] (Cp* = η5-C5Me5) with [LiBH4·THF], yielded new tungstaheteroboranes, [(Cp*W)2(μ-EPh)(μ3-E)(μ-H)(B3H2EPh)], 1 and 2 (1: E = S; 2: E = Se), and [(Cp*W)2(μ-TePh)B5H5(μ-H)3], 4. Formation of compounds 1 and 2 substantiate the evidence of [(Cp*W)2B4H10], which supports our previous studies. Compound 4 has a capped octahedral geometry that is unique due to the presence of three W-H-B bridging hydrogens in a closo cluster. Alternatively, the shape of cluster 4 can be defined as oblatoarachno that can be derived from a heptagonal bipyramid. All the compounds have been characterized by mass spectrometry, 1H, 11B{1H}, IR and 13C{1H} NMR spectroscopy in solution and the structural architectures of 1 and 4 were unequivocally established by X-ray crystallographic analysis. The density functional theory calculations also yielded geometries in close agreement with the observed structures. © 2019 Elsevier B.V.

Metallaheteroboranes containing group 16 elements: An experimental and theoretical study

In an effort to synthesize supraicosahedral iridaboranes, pyrolysis of [Cp∗IrCl2]2 with excess [BH3·THF] was carried out, and this synthesis afforded the isomeric iridaborane [(Cp∗Ir)2B6H6] clusters 1 and 2. The geometry of 1 was determined to be dodecahedral, i.e., similar to that of [B8H8]2-, whereas 2 was found to exhibit a cluster shape that can be derived from a nine-vertex tricapped trigonal prism by removing one of the capped vertices. The calculation of a large HOMO-LUMO gap further rationalized the isocloso structures for these isomers. © The Royal Society of Chemistry 2016.

Chemical Communications

Hypoelectronic isomeric diiridaboranes [(Cp∗Ir)2B6H6]: The "rule-Breakers"(Cp∗ = η5-C5Me5)

A series of novel isocloso-diiridaboranes [(Cp∗Ir)2B6H6], 1, 2; [1,7-(Cp∗Ir)2B8H8], 4; [1,4-(Cp∗Ir)2B8H8], 5; [(Cp∗Ir)2B9H9], 8; isonido-[(Cp∗Ir)2B7H7], 3; and 10-vertex cluster [5,7-(Cp∗Ir)2B8H12], 6 (Cp∗ = η5-C5Me5) have been isolated and structurally characterized from the pyrolysis of [Cp∗IrCl2]2 and BH3·thf. On the other hand, the corresponding rhodium system afforded 10- and 11-vertices clusters [5-(Cp∗Rh)B9H13)], 7, and [(Cp∗Rh)2B9H9], 9, respectively. Clusters 1 and 2 are topological isomers. The geometry of 1 is dodecahedral, similar to that of its parent borane [B8H8]2-, in which two of the [BH] vertices are replaced by two [Cp∗Ir] fragments. The geometry of 2 can be derived from a nine-vertex tricapped trigonal prism by removing one of the capped vertices. Compounds 4 and 5 are 10-vertex isocloso clusters based on a 10-vertex bicapped square antiprism structure. The only difference between them is the presence of a metal-metal bond in 5. The solid-state structures of 8 and 9 attain an 11-vertex geometry in which a unique six-membered B6H6 moiety is bonded to the metal center. In addition, quantum-chemical calculations have been used to provide further insight into the electronic structure and stability of the clusters. All the compounds have been characterized by IR and 1H, 11B, and 13C NMR spectroscopy in solution, and the solid-state structures were established by X-ray crystallographic analysis. © 2016 American Chemical Society.

Inorganic Chemistry

Hypoelectronic 8-11-Vertex Irida- and Rhodaboranes

We report the synthesis, isolation and structural characterization of several moderately air stable nido-metallaboranes that represent boron rich open cage systems. The reaction of [Cp∗CoCl]2, (Cp∗ = η5-C5Me5), with [BH3·thf] in toluene at ice cold temperature, followed by thermolysis in boiling toluene produced [(Cp∗Co)B9H13], 1 [(Cp∗Co)2B8H12], 2 and [(Cp∗Co)2B6H10] 3. Building upon our earlier reactivity studies on rhodaboranes, we continue to explore the reactivity of dicobalt analogues of octaborane(12) cluster 3 with [Fe2(CO)9] and [Ru3(CO)12] at ambient conditions that yielded novel fused clusters [Fe2(CO)6(Cp∗Co)2B6H10], 4 and [Ru4(CO)11(Cp∗Co)2B3H3], 5 respectively. In an attempt to synthesize a heterometallic metallaborane compound we performed the reaction of [(Cp∗Rh)2B6H10], 6 with [Cp∗IrH4] that yielded a Ir-Ir double bonded compound [(Cp∗Ir)2H3][B(OH)4], 7. All the new compounds have been characterized by IR, 1H, 11B, 13C NMR spectroscopy, and the molecular structures were unambiguously established by X-ray diffraction analysis. This journal is © The Royal Society of Chemistry.

Fulltext

Dalton Transactions

Chemistry of group 9 dimetallaborane analogues of octaborane(12)

We report the synthesis, isolation and structural characterization of several crystalline, moderately air stable nido-metallaboranes which represent novel metal rich open cage systems.The reaction of [Cp*CoCl]2, (Cp* = ν5-C5Me5), with [LiBH 4·thf] in toluene at-78 °C, followed by thermolysis with [BH3·thf] in boiling toluene yielded clusters, [(Cp*Co)3B6H8O] (1) and [(Cp*Co)2B8H11Me] (2). Under the similar reaction condition, [Cp*RhCl2]2 yielded [(Cp*Rh)3B7H11] (3) and [(Cp*Rh)2B8H12] (4). All the new compounds, 1-4 have been characterized by elemental analysis, IR, 1H, 11B, 13C NMR spectroscopy, and the geometric structures were unequivocally established byX-ray diffraction analysis of compound 1-4. Quantum chemical calculation by using density functional theory method is implemented on model compounds 10-40 (10-40 are the Cp analogs of 1-4 respectively, Cp = C5H5) and yields geometries in agreement with the X-ray detaermined geometries. Large HOMO-LUMO gaps are in tally with the higher stabilities of 10 and 30. © The National Academy of Sciences, India 2014.

Proceedings of the National Academy of Sciences India Section A - Physical Sciences

Synthesis, characterization and electronic structures of Rh and co analogs of decaborane-14

Cluster expansion reactions of cobaltaboranes were carried out using mono metal-carbonyls, metal halides and dichalcogenide ligands. Thermolysis of an in situ generated intermediate, obtained from the reaction of [Cp*CoCl] 2 (Cp* = C5Me5) and [LiBH 4·thf], with three equivalents of [Mo(CO)3(CH 3CN)3] followed by the reaction with methyl iodide yielded isocloso-[(Cp*Co)3B6H7Co(CO) 2] (1) and closo-[(Cp*Co)2B2H 5Mo2(CO)6I] (2). Cluster 1 is ascribed to the isocloso structure based on a 10-vertex bicapped square antiprism geometry. In a similar manner, the reaction of [Cp*CoCl]2 with [LiBH 4·thf] and the dichalcogenide ligand RS-SR (R = 1-OH-2,6-(tBu)2-C6H2) yielded nido cluster [(Cp*Co)2B2H2S2] (3). In parallel with the formation of the compounds 1-3, these reactions also yielded known cobaltaboranes [(Cp*Co)2B4H 6] (4) and [(Cp*Co)3B4H4] in good yields. After the isolation of compound 4 in good yield, we verified its reactivity with PtBr2, which yielded closo-[(Cp*Co) 2B4H2Br4] (5). To the best of our knowledge this is the second perhalogenated metallaborane cluster which has been recognized. All the new compounds were characterized by elemental analysis, IR, 1H, 11B, and 13C NMR spectroscopy, and the geometric structures were unequivocally established by the X-ray diffraction analysis of compounds 1, 2, 3 and 5. Geometries obtained from the electronic structure calculations employing density functional theory (DFT) are in close agreement with the solid state X-ray structures. In addition, we analyzed the variation in the stability of the model compounds 1′ (1′: Cp analogue of 1, Cp = C5H5), [(CpCo)4B 6H6] (1a) and [(CpRh)4B6H 6] (1b). © 2014 The Royal Society of Chemistry.

Synthesis, characterization and crystal structure analysis of cobaltaborane and cobaltaheteroborane clusters

Metal rich metallaboranes of group 9 transition metals

Journal	Data powered by TypesetJournal of Organometallic Chemistry
Publisher	Data powered by TypesetElsevier B.V.
ISSN	0022328X
Open Access	No